Sledger crusher

ABSTRACT

A crushing mill comprising a casing having a plurality of hammers mounted to revolve about a horizontal axis and within which casing cradles provided with grid bars whose position is adjustable in relation to the rotation path of the hammers, the cradles at their adjacent ends having a common fulcrum, the improvement in which means is provided for effecting adjustment of both cradles in unison by shifting the axis of the fulcrum inwardly or outwardly relative to the path of the hammers.

United States Patent n91 MacMaster et al.

SLEDGER CRUSHER Inventors: Malcolm John MacMaster; Kenneth John George MacMaster, both of Stourbridge, England Assignee: Frances & John S. Lane Limited,

Brierley, England Filed: Dec. 17, 1971 Appl. No.: 209,207

Foreign Application Priority Data Nov. 5, 197i Great Britain 51,553/71 US. Cl. 241/69, 241/89.1 Int. Cl. B021: 13/02 Field of Search 241/73, 89.], 239,

References Cited UNITED STATES PATENTS Speer 241 239 x Jan. 1, 1974 2,149,571 3/1939 Battey 24l/89.1 X

Primary Examiner-Donald G. Kelly Assistant Examiner-Gary L. Smith Attorney-Donald M. Wight et a1.

[57] ABSTRACT A crushing mill comprising a casing having a plurality of hammers mounted to revolve about a horizontal axis and within which casing cradles provided with grid bars whose position is adjustable in relation to the rotation path of the hammers, the cradles at their adjacent ends having a common fulcrum, the improvement in which means is provided for effecting adjustment of both cradles in unison by shifting the axis of the fulcrum inwardly or outwardly relative to the path of the hammers.

11 Claims, 3 Drawing; Figures SLEDGER CRUSHER This invention relates to a crushing mill or so-called sledger crusher and more particularly to a mill having a crushing chamber in which hammers are mounted to revolve about a horizontal axis for exerting a crushing action on the material against grid bars attached to beams, each beam being pivotally suspended for adjustment about one end towards and away from the path swept out by the hammers.

According to the present invention in a crushing mill of the type set out the cradles at their meeting ends have a common fulcrum and adjustment of the cradles is effected by movement of the axis of the fulcrum inwardly or outwardly relative to the path swept out by the hammers.

This arrangement has the advantage that adjustment of the cradles and their associated grid bars takes place in unison and can be effected by the same adjusting mechanism.

The invention is illustrated in the accompanying drawings in which:

FIG. 1 is an elevation of a sledger crusher having two adjustable beams constructed and arranged for adjustment in accordance with a preferred embodiment of the invention;

FIG. 2 is a detailed sectional view on an enlarged scale showing the common fulcrum for the two beams, and

FIG. 3 is a view on the line IIIIII of FIG. 2.

The sledger crusher of this invention comprises a casing including side plates, one of which is indicated at S in FIG. 1 and within the crushing chamber enclosed between which is a hammber system indicated in dotted lines at H fast on a horizontal shaft A, the bearings B of which are carried by pedestal brackets built into the side walls of the casing.

The crushing action is set up by the rotary movement of the hammers which co-operate with arcuate grid bars 1 and 2 respectively supported by cradles or beams 3 and 4. Beam 3 is pivotally suspended at its upper and upstream end about a shaft 5, being secured at its other end to a shaft 6 which also functions as a fulcrum for the cradle 4 of the second grid 2. It should be stated that the shafts 5 and 6 impart transverse stiffness to the cradle 3, shaft 6 being common to both cradles 3 and 4, and a further shaft 7 imparts stiffness to the cradle 4.

As wear occurs it is necessary to take up clearance between the path swept out by hammers and the grid bars 1 and 2 and hitherto in known arrangements adjustment of the cradles has been effected independently, which can give rise to difficulties. By providing a common fulcrum 6 for the cradles 3 and 4 it makes possible the provision of a single means of adjustment for both cradles which in the preferred embodiment illustrated is by means of a wedge device indicated generally at 8.

Mounted externally of the side plates S of the casing are guides for each of the shafts and for this purpose both shafts 6 and 7 are extended so as to project beyond each side plate.

As can be seen from FIGS. 2 and 3, the shaft 6 issup ported at its ends in a bearing block 10 which is slidably .mounted in axially spaced pairs of bars 11 and 12 whichare shouldered. These guide bars which are built onto the side plate of the casing extend at an angle to the horizontal.

The bearing block 10on its upper side has a seating face 13 extending at right angles to the guide bars and cooperating with the seating are the headed ends of a pair of thrust screws 14 which engage screw holes in an inclined bracket 15 on the casing. 16 are lock nuts.

On its other and lower side, block 10 has an angled seating face 20 for co-operation with a wedge plate 21, the latter being mounted for traversing movements on a slide 22. Movement is imparted to the wedge block 21 by a threaded spindle 23, the latter extending through a vertical side wall 24 of an open sided housing, the other two walls of which are indicated at 25 and 26. It will be seen that the spindle 23 projects through the side wall 24 and carries adjusting nuts 27 and 30 and a locknut 28. At its other end spindle 23 is pivotally connected to the wedge plate 21 through a slidable U-bracket 31, the underface of which abuts against the slide 22. Spindle 23 is pivotally anchored to bracket 31, the pivotal connection between bracket 31 and wedge 21 being at 32. On the opposite and vertical end of wedge 21 are sockets 33 to receive elongated adjusting screws 34 which extend through openings in the wall 26 and are provided on opposite sides of the wall with nuts 35, 36.

It will be seen that if it is required to adjust for taking up wear the wedge 21 has to be moved in the direction of arrow X and prior to making such an adjustment it is necessary to slack off nuts 35, 36 and lock nuts 16 and withdraw screws 14, back off adjusting nut 30 and lock nut 28 and then turn the nut 27 to shorten the effective length of spindle 23.

Shaft 7 is similarly mounted at its ends, projecting beyond the casing in bearing blocks 40 slidablein inclined guides 41 but in this case no provision for adjustment is necessary since adjustment of both cradles is effected through the wedge device 8. It should also be noted that in order to ensure stability the guide bars 11 and 12 for the bearing blocks 10 and also for the blocks 40, the flanges provided by their shouldered section protrude over the blocks, the bars 11 and 12 also being extended downwardly to overlie and provide a steady for the wedge plate 21.

There is no need for any wedge or holding screws around the bearing blocks for shaft 7 because, as previously stated, shaft 6 being fixed in position, any movement of shaft 7 could only take place in a radial direction, i.e. about the axis of shaft 6. Since the movement of shaft 7 is determined by its slides 41 it will remain immovable. In FIG. 1 the chain lines show the position of the fulcrum (shaft) 6 on adjustment to take up wear of the grid bars, the adjusted position of shaft 6 being indicated at 6a. Resulting from the movement of shaft 6a the shaft 7 supporting the free end of cradle 4 will be forced to ride up its guides 41 to the position shown at 7a.

In practice the radial centres of the grid bars 1 and 2 are not concentric to the rotation centre of the hammers H but are so selected as to give a progressive wedging action. This wedging action can be maintained by suitable choice of the relative angularity of the planes in which the shafts 6 and 7 are caused to move.

As can be seen from FIG. 3, the wedge plate 21 tits and thus moves between the two pairs of bars 11 and 12. To permit of adjustment of shafts 6 and 7 elongated slots as shown at.6' and 7' are cut in the side walls.

In operation and assuming an adjustment is necessary to take up clearance, the necessary adjusting and lock nuts and screws are slackened off, a pull is applied to the wedge 8 at each side of the casing through the adjusting screw 23 when it will move to the left as indicated by arrow X. It follows that the sliding and wedging action of each plate 8 through its inclined face 20 on the block will lift the bearing blocks and hence shaft 6 and the entire cradle assembly 3 and 4. Conversely, when the wedge 21 is pushed to move it to the right gravity will maintain the block 10 and face in sliding contact although there is no actual linkage between the two. lt will be appreciated that should there be any stiffness in the assembly the holding screws 16 can be used to assist in this pushing operation. It will be understood from the foregoing that the guides and bearing blocks for the shafts 6 and 7 are repeated on both side walls of the casing together with the wedge adjustment 8.

ln existing forms of adjustment, turn buckles which are manually operated have to be operated in unison, otherwise binding takes place between them, whereas with the adjustment mechanism of the present invention should an operator on one side of the machine get ahead of his colleague on the other side, while he will have more work to do, no binding in the threades of the adjusting spindle will occur. Furthermore, there is the added advantage that a wedge device is easier to callibrate for movement than a turn buckle. Another advantage arising from the provision of bearing blocks to support the shafts 6 and 7 is that the main forces on the shaft, which are downwards, will be transmitted directly and positively to the under frame of the machine and also are distributed over a relatively large area of the casing.

By reason of the fact also that five adjustment screws are used to hold the shaft 6 in position smaller screws can be fitted as compared with the case when using a turn buckle having a single adjusting screw.

We claim:

1. In a crushing mill comprising a casing, a hammer system including hammers mounted to revolve about a horizontal axis therein and grid bars having adjustable mounting means mounting the same for selected positioning in relation to the path swept out by the hammers as the grid bars and hammers wear, the improvement in which said mounting means includes a first cradle and a second cradle in which cradles the grid bars are respectively secured with each grid bar in relation to the path of the hammers exerting an independent wedging action, the first cradle having a leading end mounted on a fixed fulcrum for pivotal movements about said fulcrum and a trailing end supported on a shaft extending transversely of the casing, said shaft providing a fulcrum for a forward end of the second cradle, further means supporting said second cradle other end for sliding movements relative to the casing, means including bearings carried by the casing on which said shaft is supported and adjusting means for raising or lowering said bearing and pivoting said cradles substantially as a unit about said fulcrum and restoring the original relationship of said grid bars with respect to the worm hammers.

2. A crushing mill as claimed in claim 2 in which said adjusting means for the bearings for the shaft includes means for exerting a wedging lifting action thereon.

3. A crushing mill as claimed in claim 1 wherein the bearings for the shaft common to each cradle are supported in bearing blocks and the casing includes side walls having inclined guide bars in which the bearing blocks are slidably mounted.

4. A crushing mill as claimed in claim 3 in which said adjusting means includes each bearing block having formed on its underside with an inclined seating, and a wedge plate cooperatively engaging each inclined seating and slidably supported on guides on the casing for adjustment in opposite direction.

5. A crushing mill as claimed in claim 4 in which thrust screws are provided for engagement with the upper side of the bearing blocks for maintaining contact between the bearing blocks and the wedge plates.

6. A crushing mill as claimed in claim 5 in which adjustment of each wedge plate is by means of threaded spindles provided at opposite ends thereof.

7. A crushing mill as claimed in claim 1 in which said further means supporting the other end of the second cradle includes a second transverse shaft, and guide means freely slidable supporting said second transverse shaft.

8. A crushing mill as claimed in claim 7 wherein said second transverse shaft extends beyond the side walls of the casing, and said guide means includes a bearing block supporting each end of said second transverse shaft, said bearing blocks being slidable mounted in guide bears on the casing.

9. A crushing mill as claimed in claim 3 in which thrust screws are provided for engagement with the upper side of the bearing blocks for maintaining contact between the bearing blocks and the wedge plates.

10. A crushing mill as claimed in claim 9 in which adjustment of each wedge plate is by means of threaded spindles provided at opposite ends thereof.

11. A crushing mill as claimed in claim 4 in which adjustment of each wedge plate is by means of threaded spindles provided at opposite ends thereof. 

1. In a crushing mill comprising a casing, a hammer system including hammers mounted to revolve about a horizontal axis therein and grid bars having adjustable mounting means mounting the same for selected positioning in relation to the path swept out by the hammers as the grid bars and hammers wear, the improvement in which said mounting means includes a first cradle and a second cradle in which cradles the grid bars are respectively secured with each grid bar in relation to the path of the hammers exerting an independent wedging action, the first cradle having a leading end mounted on a fixed fulcrum for pivotal movements about said fulcrum and a trailing end supported on a shaft extending transversely of the casing, said shaft providing a fulcrum for a forward end of the second cradle, further means supporting said second cradle other end for sliding movements relative to the casing, means including bearings carried by the casing on which said shaft is supported and adjusting means for raising or lowering said bearing and pivoting said cradles substantially as a unit about said fulcrum and restoring the original relationship of said grid bars with respect to the worn hammers.
 2. A crushing mill as claimed in claim 2 in which said adjusting means for the bearings for the shaft includes means for exerting a wedging lifting action thereon.
 3. A crushing mill as claimed in claim 1 wherein the bearings for the shaft common to each cradle are supported in bearing blocks and the casing includes side walls having inclined guide bars in which the bearing blocks are slidably mounted.
 4. A crushing mill as claimed in claim 3 in which said adjusting means includes each bearing block having formed on its underside with an inclined seating, and a wedge plate cooperatively engaging each inclined seating and slidably supported on guides on the casing for adjustment in opposite direction.
 5. A crushing mill as claimed in claim 4 in which thrust screws are provided for engagement with the upper side of the bearing blocks for maintaining contact between the bearing blocks and the wedge plates.
 6. A crushing mill as claimed in claim 5 in which adjustment of each wedge plate is by means of threaded spindles provided at opposite ends thereof.
 7. A crushing mill as claimed in claim 1 In which said further means supporting the other end of the second cradle includes a second transverse shaft, and guide means freely slidable supporting said second transverse shaft.
 8. A crushing mill as claimed in claim 7 wherein said second transverse shaft extends beyond the side walls of the casing, and said guide means includes a bearing block supporting each end of said second transverse shaft, said bearing blocks being slidable mounted in guide bears on the casing.
 9. A crushing mill as claimed in claim 3 in which thrust screws are provided for engagement with the upper side of the bearing blocks for maintaining contact between the bearing blocks and the wedge plates.
 10. A crushing mill as claimed in claim 9 in which adjustment of each wedge plate is by means of threaded spindles provided at opposite ends thereof.
 11. A crushing mill as claimed in claim 4 in which adjustment of each wedge plate is by means of threaded spindles provided at opposite ends thereof. 